21216347958968 has 32 divisors (see below), whose sum is σ = 40544579043360. Its totient is φ = 10404592049280.

The previous prime is 21216347958943. The next prime is 21216347958973. The reversal of 21216347958968 is 86985974361212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6950468 + ... + 9525843.

It is an arithmetic number, because the mean of its divisors is an integer number (1267018095105).

Almost surely, 2^{21216347958968} is an apocalyptic number.

It is an amenable number.

21216347958968 is a deficient number, since it is larger than the sum of its proper divisors (19328231084392).

21216347958968 is a wasteful number, since it uses less digits than its factorization.

21216347958968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16479407 (or 16479403 counting only the distinct ones).

The product of its digits is 313528320, while the sum is 71.

The spelling of 21216347958968 in words is "twenty-one trillion, two hundred sixteen billion, three hundred forty-seven million, nine hundred fifty-eight thousand, nine hundred sixty-eight".